The present invention relates to circuits useful in electronic measuring instruments. More particularly, it relates to circuits used to detect the edges of pulses, and the application of such circuits to an oscillator useful in measuring instruments and in frequency encoding of digital signals or data for transmission purposes.
There are many types of pulse shaping circuits which are used to detect the leading edge, or trailing edge of a pulse. Many of these circuits produce output signals which undergo a transition in logic level at times other than the occurrence of transitions in the applied input pulse. For example, generally the leading edge or trailing edge of the output pulse will be delayed by a fixed time interval with respect to that of the input pulse. While useful in many applications, fixed delays do not facilitate the encoding of information on to the output waveform.
The principal object of the present invention is to provide an edge detector circuit wherein the width of the output pulses can be readily controlled.
An object of the invention to is provide an edge detector circuit wherein the output waveform is readily varied in accordance with a variable propagation delay.
Another object of the invention is to provide a circuit which performs a frequency doubling function.
Still another object of the invention is to provide a circuit which is useful for detecting sudden changes in a signal produced by a transducer
Yet another object of the invention is to provide a circuit useful for making delay measurements
Another object of the invention is to provide a circuit useful for performing pulse width modulation
Still another object of the invention is to provide an oscillator wherein frequency of oscillation varies in a known manner in accordance with circuit delays
Yet another object of the invention is to provide an oscillator wherein the values of at least two variables may be encoded into the output waveform.
Another object of the invention is to provide an oscillator having an output which is turned on or off in response to a logic control signal.
Still another object of the invention is to provide an oscillator which may be made up entirely of integrated circuit logic components.